Why do energy storage systems need special fuse inserts?

More energy storage systems are installed globally every day. Present-day battery systems often reach power outputs of several hundred MWh. That requires advanced protection using special fuse inserts. They have to dramatically reduce the current in response to a short circuit and interrupt it very quickly as well.

Why do batteries need fuses?

Modern-day battery and energy storage systems place huge demands on fuses. Constantly rising power levels at maximum DC voltages of 1500 V can generate short-circuit currents of several hundred kiloamperes. Another issue relates to load profiles produced by a wide variety of loading and unloading cycles.

What is a high voltage fuses?

In general, high-voltage fuses (defined as fuses rated above 1.000 V a.c.) are physically larger and generally more complex than low voltage fuses due to their need to operate at much higher voltages. HV fuses may perform one or both of two primary functions.

What are HV fuses?

HV fuses, often named also HH fuses are High-voltage High-rupturing capacity fuses designed for alternating voltages >1 kV. Protection of transformers for power distribution networks is the most widely spread application of HV fuses.

What is the difference between backup fuses and general-purpose fuses?

Backup CL fuses can only interrupt currents higher than a defined value (rated minimum interrupting [breaking] current). General-purpose fuses can interrupt quite low currents, compared to backup fuses, but for convenience were tested at a current corresponding to a melting time of one hour.

How does voltage affect a fuse?

However, this voltage does help support the system, reducing the duration of a voltage dip in parallel circuits, caused by the fault, just to the melting time of the fuse. The lowest current at which a fuse shows this current-limiting effect, called its “threshold current”, is usually about 20 to 30 times the fuse’s current rating.